Long-term exposure to polluted air is significantly increasing both cancer risks and cancer-related deaths worldwide, with women, children and low-income communities bearing the heaviest burden, according to a major new global report that warns air pollution is now emerging as one of the world’s deadliest preventable health threats.
The report, commissioned by the Union for International Cancer Control, says the scientific evidence linking air pollution and cancer has become strong enough to justify immediate policy action from governments around the world.
Researchers warned that without urgent intervention, rising pollution levels could undermine decades of progress in global cancer prevention and treatment.
The review, titled Clean Air in Cancer Control: An Overview of the Evidence, analyzed findings from 42 meta-analyses and systematic reviews published between 2019 and 2024, making it one of the most comprehensive assessments yet of the relationship between air pollution and cancer.
According to the report, prolonged exposure to fine particulate matter known as PM2.5 increases the overall risk of developing cancer by 11% and raises the risk of dying from cancer by 12%.
Researchers found that the impact extends far beyond lung cancer, with strong links also identified for liver, colorectal and breast cancers.
The report found that rising PM2.5 exposure is associated with a 32% higher incidence of liver cancer and an 18% increased likelihood of colorectal cancer.
Cancer mortality risks also rise sharply with worsening air quality, including a 20% higher risk of death from breast cancer, 14% from liver cancer and 12% from lung cancer.
Researchers estimate that ambient air pollution now contributes to around 434,000 lung cancer deaths globally every year.
The report says polluted air accounts for more than a quarter of preventable lung cancer cases among women and nearly one in six among men.
Experts involved in the report warned that the burden is not shared equally.
Developing countries, already struggling with rising cancer rates and limited healthcare capacity, are facing the greatest risks.
The report identified South Asia, Africa and countries in the Eastern Mediterranean region as areas with the highest pollution-related cancer burden.
Former New Zealand prime minister Helen Clark said vulnerable communities are disproportionately affected, particularly women and children living in households that rely on solid fuels for cooking and heating.
“These are the human faces of environmental injustice,” she wrote in the report’s foreword.
According to the findings, women exposed to household air pollution face a 69% higher risk of lung cancer alongside elevated risks of cervical cancer.
Outdoor laborers and communities living near industrial zones and factories were also identified as high-risk groups, particularly in economically deprived areas where pollution exposure is concentrated.
The report warned that the crisis could worsen dramatically over the coming decades as global cancer cases are projected to rise from 20 million in 2022 to 35 million by 2050, placing enormous pressure on already strained healthcare systems.
Cary Adams, chief executive officer of UICC, said polluted air is silently reversing gains made in reducing cancer deaths.
“We have made huge strides in reducing deaths from cancer, but polluted air is silently undermining that progress,” he said.
Experts stressed that unlike many other cancer risks, air pollution is often unavoidable for ordinary people.
Elisabete Weiderpass, director of the International Agency for Research on Cancer, said air pollution should now be recognized alongside tobacco, alcohol and infections as a major preventable cause of cancer.
The report said reducing exposure depends largely on government policies involving transport, industry, energy and urban planning.
Recommended measures include stricter vehicle and industrial emission standards, transitions toward cleaner energy and cooking systems, expanded air-quality monitoring and urban planning that prioritizes public transport, cycling and walking.
The report cited examples from cities such as Barcelona and Bogotá, where policies reducing traffic and encouraging cleaner transportation have already contributed to measurable declines in preventable deaths.
Although more than 140 countries have adopted air-quality standards, researchers warned that only about one-third consistently enforce them, leaving millions exposed to avoidable health risks every day.
Nina Renshaw, head of health at the Clean Air Fund, said the issue now requires the same level of political urgency as tobacco control.
“Air pollution is now responsible for more deaths every year than tobacco,” she said, warning that cleaner air policies are urgently needed to prevent a major rise in cancer cases in coming decades.